Question

Using Regular Expression.

1. Write the regular expression that matches any string that ends with a capital letter.

2. Write the regular expression that matches any string that begins with a digit, ends with a digit, and has AT MOST only one digit in the middle of the string. (* means zero or more of preceding, +means one or more and ? means 0 or 1 (we did not look at the ? in class))

So your answer should match

12 (begins and ends with a digit with nothing between)

2jfgkdjdlk5kjfdsdsj3 (begins and ends with a digit with one digit in middle)

345 (begins and ends with a digit with one digit in middle)

3ert5 (begins and ends with a digit with no digits in middle)

But does not match 3456 (too many digits) abds23 (does not start with a digit) etc.

Answer 1

1. Answer = .*[A-Z]

2. Answer = [0-9][^0-9]*[0-9][^0-9]*[0-9]

-> Starting with 0-9

-> [^0-9]* is for 0/more characters that are not digits

-> [0-9]? means 0/1 occurrence of a digit.

-> Ending with 0-9

Please up vote. Happy Learning!